I am experiencing the same issue as above. Appears it may have happened after I tried to change some settings for the plugin. Tried uninstalling, deleting all the files, and reinstalling. No dice. Thanks for your assistance with this one!

Confirmed what’s happening here… if you go into the Manual Image Crop settings and hide some of the items (like thumbnail), you break the plugin. I’m hosting with WPEngine and no content changes had been made to one of my sites so I was able to roll back and get functionality. However, on one of my other sites, content changes are made on almost a daily basis so that client is hosed right now until a patch is implemented.